[GHC] #15510: Qualified Holes

[GHC]

#15510: Qualified Holes
-------------------------------------+-------------------------------------
           Reporter:  andrewthad     |             Owner:  (none)
               Type:  feature        |            Status:  new
  request                            |
           Priority:  low            |         Milestone:  8.6.1
          Component:  Compiler       |           Version:  8.4.3
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 Let us consider the following example code:

 {{{
 import qualified Data.Map as M

 main :: IO ()
 main = print (M._ (\k v acc -> k + v + acc) 0 myMap)

 myMap :: Map Int Int
 myMap = ...
 }}}

 This errors with `Not in scope: M._`. It would cool if GHC instead treated
 `M._` as a hole but only gave suggestions from the module `Data.Map`. So,
 in this case, it would suggest things like `Data.Map.foldrWithKey` and
 `Data.Map.foldlWithKey`.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15510>
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